Telephone system



July 26, 1932. T. F. cRocKER 1,869,007

TELEPHONE SYSTEM Filed Jam 20, 1930 6 Sheets-Sheet, 1

RTE-FTW Thomas F'. crackin July 25,1932- T. F. cRocKER TELEPHONE SYSTEM Filed Jan. 2o, 195o 6 She@CAE-SheetA 2 .99u wem v @E m w @E @i July 26, 1932.

T. F. c :RocKER 1,869,007

TELEPHONE SYSTEM Filel Jan. 2o. 195o 6 sheets-Sheet. 3

IE-n- Thomas Fl Cracker' July 26, 1932. T. F. cRocKl-:R 1,869,007

TELEPHONE SYSTEM Filed Jan, 20, 1930 6 Sheets-Sheet 4 y Thames F. Cracker* 6 Shts-Sheet 5 T, F. CROCKER v TELEPHONE SYSTEM Filed Jan. 20, 1930 July 26,- 1932 Patented July 26, 1932 UNITED STATES 'PATENT Noi-Flca THOMAS F. CEOCKERLOF CHICAGO, ILLINOIS, ASSIGNOR, BY MESNE ASSG-NMENTS, TO

ASSOCIATED ELECTRIC LABORATORIES, INC., OF CHCAGO, ILLNOIS, A CORPORA- TION OF DELAWARE TELEPHONE svs'rnifi .fippnfaaion sied January 2o, 1930. semi 110.421,93).

n usual jack and cord circuits at the toll operators position are eliminated.

In most automatic telephone systems it is common practice to provide a separate group of automatic switches for use by the toll operators in completing toll calls to subscribers lines. These switches, together with their interconnecting trunk lilies, Jform what is knownas a toll serviceftrunking system. In large telephone systems a somewhat similar arrangement'known as a toll switching sysl tem is provided for interconnecting toll lines at a toll switching center. Specialtrunkilgsystems are likewise provided for handling outgoing toll calls originating in the area served by a toll board. In, all of these systems the usual method of completing connections is by means of cord circuits and the jacks in which the toll lines and trunks terminate. The objectionable features inherent in systems employing cord circuitsV are overcome in the present invention byfthe complete elimination of such cords.

The operations involved in setting up connections in systems of the above type, depend more or less on the size of the system. In the. larger systems the incoming` calls are usually answered by one operator and ,completed by another operator. The answering or A operator rout-es a call to the proper completing or B position usually by means of an order wire. The operator at the completing position then extends the call to the wanted subscriber over the usual toll Vservice' trunking system. The A operator may also be provided with the equipment for completing a call to a wanted subscriber and also with apparatus for interconnecting toll lines for switching purposes. The completing operator may also be required to handle outgoing toll calls originating in the area served by the toll office. These calls may be completed directly by the operator while the calling subscriber waits on the line, or may be recordedror completing at a later time.

E'liicientroutine methods 'for handling such toll connections have been developed in practice and Vhave become more or less standardized throughout the telephone industry. The operating personnel of most telephone companies have been trained in the use o these methods, hence, radical changes Vare not desirable. The present invention provides a more efficient and practical system Yfor supplying toll serviceof the above kind while. maintaining theessential features of standardized operation. l

The scope of the invention is broadly in-f dicated inthe foregoing paragraphs. .Various features relating-to theoperation of the system as awhole will not be specifically mentioned atthis time., but will be described in the specification `and pointed out in the appendedclaims.V Y E Fig. l shows the A operators equipment consisting of the position/apparatus Pfand the operators telephone set T. The position apparatus is common to all toll lines incoming to the position and is provided with a calling device CD andthe usualring'ing,

diallin frW splitting and monitoringkevs. In

`this figure is also shown the apparatus OW which is located at the answering position and is associated-with an order wire extendingtothe completing position.

In Fig. 2 is shown the apparatus at a B operators position. This apparatus is similar in most respects to the apparatus shown in Fig. l, and includes position equipment P',

an operators telephone set T, and terminal apparatusOlV associated with an order wire extending from the answering position. Y.

' Fig. 8 shows the toll lines TL and TL the 'former terminating in the relay group TR. This relay group, and other similarvrelay groups which terminate trunks such as TL, are multiply connected Vwith the position equipment of the A yoperators position.

Each relay group is provided with a branch extending to a toll selector TS and with a branch accessible to the B operators linder switch F.

In Fig. 4 is shown the B operators finder switch F by means of which the operator can connect with a calling toll line and complete an incoming toll call. A recording and completing trunk circuit BC, also shown in this figure, is accessible to subscribers of the automatic exchange 4and is provided with a ,trunk terminating in the selector TS which has access to outgoing toll lines via connector TC. Trunk RC and other similar trunks are multiply connected with the position equipment of the B position.

In Fig. 5 is shown the toll selector TS associated with trunk relay group such as the relay group TR, (Fig. 2). This selector has access to toll line connectors, such as the Connector TC, and to toll service trunks, such as the trunk extendingrto toll transmission selector TTS (Fig. 6). The toll line connector TC is also accessible to the toll selector associated with the recording-completing trunk of the B position.

In Fig. 6 is shown, is skeleton form, a toll selector TS', 'toll transmission selector TTS, a regular exchange toll connector C, lineswitch LS, and a local first selector S. The circuit of the selector` TS is identical with that of the toll selector TS (Fig. 5). This selector has access tov toll line connectors, such as the connector TC (Fig. 5), and is used by the B operator when completing outgoing toll calls. The'` remaining switches which are a part ofthe equipment of the regular automatic exchange areV of well known type commonly use-d for this purpose and since they do not form apart of the invention, it is not considered necessary to show them in detail. The general layout of the automatic exchange is clearly indicated inthe drawings.

The subscribers line from substation A terminates in the lineswitch LS which has access to the local .selector lS. These selectors fhave access to the local switches of the exchange and also to the recording-completing trunk, such as the trunk BC, ig. 4). The toll service switch train comprises trunks accessible to toll selector TS and terminating in the toll transmission selector TTS which has access to toll connectors, such as the connector C. The connectors have access to the local subscribers "lines in ythe automatic exchange.

Fig. 7 is a layout diagram showing the manner in which the various sheets of drawings should be arranged in order that the invention may be best understood.

The operation of the system may be briefly described as follows An incoming toll call is indicated by the lighting of the line lamp L of a trunk relay group, .such yas the relay group TR. The operator connects her tele phone set to the line by actuating the associated answering key K, and on being informed of the desired connection, will proceed to complete it in one of two ways. If desired, the A or answering operator may complete the call herself, first actuating the dialling key of the position equipment, then dialling up the toll selector TS, transmission selector TTS, and connector C to extend the connection to the local subscribers line. In case the A operator, for any reason, desires to transfer the call to the B operator for completion, she actuates the key K9 associated with the orderk wire OIV which causes a lamp to light at the B position. The B operator then actuates the key Kl8 associated with this order wire, and the inder switch F operates to connect with the calling toll line.

The A operator then advises the B operator of the destination ot the call, the talking circuit being by way of the finder switch F and the trunk relay group. The A operator then restores her answering key and is disconnected from the trunk. To complete the call, the B operator actuates the dialling key of her position equipment, and dials back through the linder switch to operate the toll selector TS, toll transmission selector TTS, and connector C to connect with the wanted line. When the connection is completed the B operator restores her answering key and the i'inder switch releases and restores to normal. Supervision is given to the A operator by lamps L and L2 associated with the relay groupR. When the conversation is iinished and the subscribers hang up this operator releases the apparatus by actuating the release key Kl.

The switchingoftoll calls, that is, the connection of an incom toll line to an outgoing'toll line is handled in exactly the saine manner as toll calls to local subscribers. In this case, however, the tell selector TS is operated to select a toll connector switch, such as the connector TC, which is then dialled up to the contacts of the desired toll line.

In the case of toll calls originating in the automatic exchange, the calling ysubscriber dials the code assigned to the toll recording operator and is connected with a toll recording-completing trunk, such as the trunk BC. The operator is advised of the call by the lighting of the line lamp L5 and answers by actuating the answering key Kl6 of the trunk circuit. If the call is one that can be quickly completed by the operator, she will. then actuate the dialling key of her position equipment and set up a connection to a toll trunk by way of a toll selector such as selector TS and a toll connector such es the connector TG. The usual supervision is given when the calling party hangs up or when the toll operator at the distant exchange rings oit to give the disconnect signal. In the event that the call cannot readily be completed by the operator, the call will be recorded and completed at n later time in the same manner as an incoming call.

Y The toll lines shown are arranged for simplex dialling by either of the operators. Composited trunks may also be used Without altering the trunk apparatus, and with minor changes the apparatus may be adapted for loop dialling. Having briefly described the apparatus and the operation of the invention, a detailed description ot the operation will nou7 be given. Assumev for example that a toll operator in distant exchange extends a call over the trunk TL Vcomprising vconductors 361 and 362 terminating in relay group TR. The operator at the distant exchange noW applies alternating current to the toll line to signal the A operator at the Wanted exchange. The signallingl current in the left-hand windings of repeating coil R is inducedin the right-hand Windings thereof Which is included in a circuit efrtending from line conductor 311, normally closed contacts 318, through the ivinding'ot alternating current responsive relay 301', condenser 314 to conductor 312. Relay 301 Whicl is ofthe mechanical locking type, operates in response to the alternating current on the toll line and closes a circuit from ground, normally closed contacts 332, contacts 316, through the lamp L, to battery. The lamp L lights to indicatean incomingT call. The circuit for the busy vlamp L1 is also closed by relay 301 at contacts 317. 1

On noting the lighted'condition of the line lamp L, the A operator will actuatethe keyfi associated With the `toll line. A circuit is therebyclosed from ground, normally closed contacts 341, Winding of relay 303, contacts 326, Winding of relay 302 to battery, and in parallel therewith through .normally closed contacts 334, `Winding of relay 304 to battery. Relay 302 operates, opens the circuit ot relay 301 at contacts 313` and at contacts 319 connects a busy ground to test'conductor 310 to mark the toll line busy to connectors such as the connector TC. The unlocking mechanism 315, Which is attached to the armature ot relay 302, is also actuated and restores the armatures of relay 301 to their normal position, opening` contacts 316 and 317. Line lamp L is extinguished, but busy lamp L1 continues to glow, its circuit nonT being completed Way of contacts319 and ground. Relay 303 operates and prepares circuits which Will be described later. Relay 304 operates,-and contacts 335L locks itself to ground by Way of contacts 313 of release-key K1. The impulsing circuit of toll selector TS is prepared at armature 331, a flashing disconnect signal circuit is prepared at contacts 359, and at contacts 337 and 336, respectively, battery through resistance 307 is disconnected ti .ri test conductor 310 and ground is substitute-d therefor. j

The operation of the key K also opens the direct connection between the toll line and the outgoing trunk associated With the relay group TR, and instead connects the line and trunk by Way of the position equipment. A connection may non e traced trom conductor 311, contacts oi key K, conductor 147, contacts 12.7 ot key K3, contacts 132 and 134, contacts 138 or' key K2, conductor 143, contacts 325 ot key K to conductor and from conductor 312, contacts of key K, conductor 146, contacts 123 ot' key K3, contacts 133 and' 135, contacts 139 of key K2, conductor'149, contacts 320 of key K, to conductor 349. The operators telephone set is bridged across the tivo talking conductors by Way of conductors 152 and 153. The circuit'of the telephone set is the usual one provided forv operators positions, and includes va receiver RR bridged across-one section ot the primary Winding oi a repeating coil R2, and a transmitter connected to the secondary Winding of the transformer in series With battery through an impedance 101 and ground.

An additional repeating coil R3 connected up by relay 102 is provided tor monitoring purposes. The inward or A yoperator may now converse with the calling operator over the toll lino and determine the connection required.

rThe operation ot the answering key K and relays 303 and 304 of the relay groupY TR prepared the toll selector LS toroperation by completing a circuit extending trom ground, normally closed contacts 141 ott-he dialling key K4 of the position equipment, resistance109, conductor 150, contacts 327, 344, and 331, conductor 356, thence to the toll selector TS rand by Way ot parallelr contacts521 and 536 through the Winding of impulse relay 502 tobattery. Relay 502 operates land closes the circuit oi relay 503 at contacts 523. Relay 503 operates, completes the circuit of the polariai winding o; relay 506 at contacts 526 and contacts 527 irepares the circuit of the vertical magnet. Relay 506 does not op atthis time as only its lower Winding energized.

The operator having determined the num ber of the Wanted subscriber, now actuates the dialling key K4 ot the position equipment and the previously traced operating circuit of relay 502 is switched over at contacts 142 from ground by Way ot contacts 141 to ground through the impulse contacts 130 ot the callingr device CD. llvlhen the calliner de- L., Y D

vice isfturned trom its normal position, oltnornial contacts 131 complete a circuit for relay 103 by way ot contacts 143 of the key K4. Relay` 103 operates and contacts 132 and 133 disconnects the talking conductors associated with the outgoing trunk. As the calling device returns to normal, the circuit of relay 502 is interrupted at the impulse contacts of the calling device and relay 502 lio responds :by deenergizing and reenergizing. Referring now to toll selector TS of Fig. 5, each time relay 502 falls back a circuit is closed from ground, contacts 524, 519, and 527, winding of slow-release relay 504, winding of vertical magnet 508, to battery. The circuit of relay 503 is intermittently opened at contacts 523 during the impulsing but that relay remains energized due to its slow releasing characteristic. The vertical magnet energizes in response to each impulse and steps the shaft and wipers up step-bystep. Relay 504 operates in series with the vertical magnet responsive to the First impulse, and remains operated throughout the series of impulses.

It will be assumed that the digit dialled in this instance is such that the shaft and Wipers are raised to the level in which toll service trunks, such the trunks comprising conductors 545 and terminating in transmission selector TTS, are accessible. On the irst vertical step of the wipers, offnormal contacts 511 close and relay 505 operates over a circuit including these contacts and contacts'549 and 526. Relay 505 completes a locking circuit for itself armature 530, this circuit including interrupter contacts'540, and at contacts 531 prepares a. circuit for the rotary magnet. Shortly after the last impulse of the series, relay 504 deencrgizes and closes' a circuit from ground, contacts 526, 529, and 531 through the winding ot rotary magnet- 509 to battery. Magnet 509 energizes and steps the wipers in on the tirst set of contacts in the called level. The circuit ot relay 505 is opened at interrupter contacts 540 and relay 505 deenergizes and in turn opens the circuit of the rotary magnet which also deenergizes.V In the event that the first trunk et the selected level is busy, test Wiper 542 of theY selector Will` encounter a ground applied to multiply connected contacts by another toll selector and this ground, eXtending by way of contacts 517, interrupter contacts 540, and olf-normal contacts 511, will again operate relay 505 which performs the same functions as in the previous instance. The rotary magnet will again energize and step the Wipers to the next set of contacts which will be tested in the same manner as the previous set. This testing and stepping operation will be repeated as long the test wiper encounters grounded contacts. When an idle trunk is encountered. which for the purpose of this description will be assumed to be the trunk comprising conductors and 546, the test wiper will not encounter ground and consequently relay 505 will not operate. Switching relay 501 will now operate over a circuit extending from ground, contacts 526, winding of relay 501, interruipiter contacts 540, off-normal contacts 511, through the winding of relay 505 to battery. The resistance of relay 501 is relatively high, and relay 505 will not operate over the above traced circuit. It may be noted that relay 501 was prevented from operating when the busy contact Was encountered since its Winding was shuntedxby the ground encountered by the test wiper. The test wiper is now disconnected from the upper terminal of relay 501 and connected instead to the lower terminal at contacts 517 and 518, respectively. The impulsing and release circuit ot the switch is opened at contacts 519; the impulse conductor from the operators set is connected Vup to wiper 543 .at contacts 520, but thisA connection has no utility at present; and the talking conductors 355 and 358 are connected up to the righthand windings of repeating coil R4 at contacts 516 and 522, respectively.

The toll transmission selector TTS, in which the trunks comprising 545 and 546 terminate, may be a selector such as the one-disclosed in Unit-ed States Patent No. 1,664,011, issued to John ViCkS, March 27, 1928. The various test contacts associated with ythe trunks, such as the `contacts 547 ,f are multipled in the banks of the various toll selectors and serve the purpose of marking the trunks engaged when a selector, such as the selector TS, has established a connection with the trunks. The operation of the switching relay 501 of selector TS completes a loop `eircuitfor the line relay of the transmission selector extending over conductor 545, wiper 541, Acontacts 533, upper left-hand winding ot repeating coil R4, upper winding of polarized relay 506, contacts 525 and 548, lower left-h and winding of repeating coil R4, contacts 538, wiper 544, and trunk conductor 546. The line relay ol the transmission selector operates over4 the above loop circuit and prepares that switch to receive the dial impulses. Relay506 does not operate at this time, since the battery How in its upper winding is in such a direction that the two windings of the relay oppose each other.

The operator now dials the second digit of the wanted number, and relay 502 of toll selector TS responds as in the previous instance. Each time relay 502 drops back in response to an impulse, the loop circuit to the toll transmission selector is opened at -contacts 525 and the line relay of the transmission selector responds accordingly. The Wipers of the transmission selector are raised to the called level and thev selector automatically rotates and selects an idle trunk which may be assumed to be the trunk terminating in connector C. This connector maybe similar to the one disclosed in the above referred to VVicks patent. Toll selector TS and transmission selector TTS respond to the last two digits in the usual way, the latter y repeating the impulses to connector C are advanced to the contacts of the wantedy line, for 'example, the line comprising conductors 601- lou .603 extending to substation A. If the Wanted line is busy, the test wiper of the connector will encounter a grounded contact and the busy tone will be returned to the calling operator in the usual manner. It the wanted line is idle the connector and transmission selector will switch through in the usual lcontacts 532, conductor 357, through the lamp L2 to battery. Lamp L2 lights to inform the voperator that the wanted lin-e has been seized.

The o ierator then actuates the rineinrf he K2 of the position apparatus, and alternating current is connected to the talking conductors of the trunk by way of contacts 137 and 1/10. This ringing current is transmitn ted through the repeating coil R11- ot toll selector TS, to the transmission selector-TTS to operate an alternating current responsive relay in that switch. The transmission selector, in turn, causes the connector to complete the ringing circuit in the usual manner. V-

The operator may remain on the connection or may disconnect, it desired, by restoring the answering key K, the latter operation again connectingV the toll line vdirectly through to the outgoing trunk. vRelays 302 and 303 will then `deenergize since their circuits are opened at contacts 326', and a holding circuit for impulse relay 502 of toll selector TS will be completed to ground by way of contact-s 328. lVlien the called subscriber answers, battery will be disconnected 'from the trunk conductors incoming to the transmission selector, and relay 506 of the toll se lector TS will. rest-ore to normal and open the circuit of the lamp L2. Lamp L2 is then extinguished to indicate to the operator that the called subscriber has answered the call. i The operator may tall; with either'subscriber (or operator) to the exclusion of vthe other by operating the key K and one or the other of out-off keys K6 or K7. Key K6 closes a circuit for relay 103 which disconnects the calling subscriber (or operator) and key K7 closes a circuit for relay 1011 which disconnects the called subscriber (or operator).

Then the conversation is finished, the

y called subscriber will hang up and transmission selector T TS will again connect battery to the trunk conductors 54.3 and 5/16. Relay 506 will again `operate and complete the previously traced circuitA of lamp L2 which will light to give disconnect supervision. The operator will ordinarily disregard this signal and wait for the operator in the distant exchange t-o give the usual disconnect signal. This signal is given by connecting an alternating current to the toll line at the distant office. The alternating current responsive relay 301, responds as for an incoming call and connects up the lamp L at contacts 316. Relay 304 being operated, howsJ ever, the circuit of the lamp L will extend to ground through the interrupter I, which will cause the lamp to flash in a characteristio manner. In case a lamp, such as the lamp L2, should remain in lighted condition for a` considerable time, the inward operator may cutv in on the connection and challenge the toll operator, who may desire another connection. In either case the call may be released by actuating the key K1, thereby open- 1 the circuit of relay 30a at contacts 313.

Relay 301i restores and opens the holding circuit ot relay 502 of the toll selector at con- Vtacts 331 following which the toll selector re-V leases. R-elay 502 restores and opens the circuit ot relay 503 Vwhich also restores, and in turn opens the circuit of relay 501. A circuit for release magnet 510 is then closed from ground, contacts 524, 519, and 528 and olli-normal contacts 512. net energizes to restore the wipers to normal position in the usual way, its circuit being opened at off-normal contacts 512 when the w'pers reach the normal position. The loop circuit through the toll transmission selector TTS and connector C is opened at contacts and 5118 following the release of relays 502 and 501. These switches release in the usual way and all apparatus involved in the connection is then in condition to receive another call.

The A operator may desire to listen in on a callof the character just described, to determine Whether or not the transmission is satisfactory and to check other details of the call. For this purpose the monitoring key K8 will be operated, thereby closing a circuit for relay 102 at contacts 120. Relay 102 will energize, disconnect the operators telephone set from conductors 152 and 153 at contacts 110 and 117, and at contacts 111 and 116 will connect them to the primary winding of the monitoring repeating coil R3. The receiver of the telephone set is disconnected from the usual connection to the primary winding of the repeating coil R2 and bridged across the secondary winding of the repeating coil R3 at contacts 113 and 1111. The answering key K of the toll line circuit LR will, of course, be operated and the connection extended through the position apparatus as previously described. 4When the operators set is connected up in the above manner, the operator may listen to the call Without either subscriber being aware of the fact.

In 'the foregoing description it was assumed that the A operator completed the connection. In actual practice, however, particularly during periods ot heavy trafic, the A operator will vpass such calls to a B The release magoperator for completion.

ance with the usual operating routine now` TheA used inmodern telephone systems.

. operator answers the call in exactly the same manner as in the previous case. 303, and 304 of the relay group TR arefope-rated and toll selector TS is prepared for operation as before. wants of the'calling toll'operator, instead of dialling up the wanted number as in the previous connection, the A operator momentarily 4 actuates a key, such as thekey K9 associated such as the one shown in Fig. 2. 'A circuit is 1 with an order wire, leading to a B position,

thereby closed Vfrom ground, contacts 119, conductor 151, contacts 329, through the winding of relay 305 to battery. Relay 305Y operates, completes a locking circuit for itself to ground at the release key K1 by way of contacts 338 and 345, closesthe rotary marking circuit -at contacts 339, and connects ground to the vertical marking circuit at contacts 340, at the same time opening the original energizing circuit of relays 302 and-303 at contacts 341. Relays 302 and 303 rest-ore', the4 latter relay opening the A operators dialling..

r circuit at contacts 327 and 330. The above referred to rotary marking circuit now extends from conductor 351, contacts 339, winding of relay 306, winding` of relayr 302 to batv tcry. The conductor 351 terminatesfin inulf tiple contacts in the banks of the various Y finder switches, `such as the finden switch F,

these contacts beingy engaged by the test.. wiper of the finder switch. The operationy of the order wire key K9 also closesya circuit from ground, contacts 118, order Wire -conductor 154, throught-hewinding-of relay-209 to battery. This relay. and the-associated for the lamp L3 at contacts 242, and alcircuit *forthe lamp.` L4 atcontacts. 243. -LampL3. 4at the inward-operators `position lights tor '.indicate the busy condition offtheorderwire.

Lamp L4 at the outward '.operatorsvpo'sition l :lights .to appraise -theoperator Yof a:call

1. awaiting attention.

' The B operator on vnoting the lightedcondit-ion of lamp. L4 actuates the lockingr key .K13 ropening the circuit offrelay-209at con- "--".tacts 241.

,circuit ofl lampsV L3- and L4. LampA L4 is extinguished but -lamp .L3continues to glow Aas its circuit'now-*extends to ground by way- ,magnet 406 to battery. Rotary. magnet-'406 4voperates and rotates thewipers one stepato the Relay 209v restores and opens the ofthe key contacts 218. The starting circuit of the finder switch Fis also completed by the operation of key K13,this circuit'extendin from ground, contacts 219, starting Aconductor 254,. windingA of `relay 404, `to battery.

vRelay404 operates, opens a .pointinthere- 57 f'leasema'gnet circuitat contacts 430 and coIn-.

This is inv accord- Vmagnet 405 to battery. 'The' vertical :magnet Relays 302, i

After determining the -will beslightly retarded. Rclayi402on loptaets 424, disconnects vertical magnet 405" the vcall-ing .toll lineto. .mark thelineby connecting batteryth-roughrelays'302 land 306v to upletes 'thel automatic Y'stepping :circuit/which now extends -from;ground, contacts 432, 429, and' 420, through the "winding 'off vertical energi Zes over the vabove circuit, raises. Lthe" wipers 408-414 one step and completes a ,circuit for the lower windingof relay 403 at: contacts 434. =CRelay-403 operates,` disconnects the vertical magnet rfromftherstepping'circuit vert-ical test wiper 412 by way of contacts 424 and 428fand the upper winding offrelayf402. The vertical test wiper engages. contactsiterminating conductors, such las 'the yconductor 352 to which, as previously explained, ground' is connected at the associated relay:v` group -by-the opcrationof a relay, such as the relay 305, when-the inward operatorstarts to'translfer a call. If t-he calling toll'line--isnot located inl thelirst-level of 'the'inder'switch bank, the contacts engaged byfwiperl412, following the first vertical -step,-willA not Ibe grounded, hence -no circuitzwill be :closed-for theupper winding of'relay 402. The vertical y Ymagnet will deenergize since its-circuit hasim been opened at contact 429, and inrturnwill vopen the circuitv offrelay 403. Relay-403 will deenergize and again connect the magnet tothe-stepping circuit,-1whereonthe magnet willre/operate' and raise thef'wipersv another!gv step. Thisstepping action will continue until the wiper 412 encounters'the contacts associated vwi th the callingtolllineaat. which time the ground encountered by 'thewiperrwillw .causethe operation ofrelay 402. n'llhe res-ist-y 1 0 ance. of this relay is relatively high andwthe vertical magnet-` will* not Uoperate vin-series therewith although the `release `of the magnet erating,'completes a locking circuitfor'itselff'" at contacts423, disconnects the impulsing conductorv 246 from wiper 410 at contacts 421, prepares the rotary testing circuit at contacts 422,'opens the vertical testing circuit at confrom the stepping circuit at contacts 426, and connects up the rotary magnet 406 at contacts The wipers are .thereby stoppedvfopposite the level in which the contacts associated with the calling toll line are accessible. `With f the first vertical step 'of the wipers,.offnormal contacts 415 yclose an`V additional f point' in the vrotaryY testingfset.

Following the operation of relay 402 magnet 405 will restore andopen store, and again complete the automatic-stepping circuitwhich now. extends by way 'of contacts 425 through the winding ofrotary firstset of contacts inthe level. It-^will .be recalled that in't-ransferring a call, thefinward operatorcauses the line relay groupof A:1t-contacts 429 and connects it instead to they the circuit of relay'- 403` whichwill aflso re- 32C the rotary marking conductor 351,the terminating contact of which is engaged by ywiper 411 of the inder switch. is not the irst one in the group, wiper 411 will not encounter a potential and the stepping operation will again take place in the saine manner as previously described-vertical.

. stepping, the wipers being' advanced t-o the next set of contacts in the level. lien the line marked as calling isi'eaclied, acircuit will be completed from battery, winding'of relay 302, winding of relay 306, contacts 339, conductor 351, wiper 411 of the finder switch, upper winding of relay 401, lcontacts 422, upper winding of relay 403, contacts 431 and 415 to ground. Relay 401 operates, coin-v pletes a locking circuit for its lower winding at contacts 419, opens the locking circuit of relay 402 at contacts 435, short-circuits its own upper winding at contacts 418, and connects the various talking conductors to the wipers at contacts 416, 417, and 420. Relay 403, which was initially energized by the operation of the rotary magnet, is now heldV operated over its upper winding in the above circuit and maintains the steppingr circuit open at contacts 429. Relay 402 deenergizes and closes points in the operating circuit at contacts 421 and 427. Referring now to the toll line relay group TR, relays 302 and 306 operate over the previously traced rotary testing circuit. has no utility at this time. Relay 306 on operating closes a point iii its own circuit at contacts 346 to render it independent of the contacts 339 Vof relay 305, splits the two branches of the trunk at contacts 342 and 347, transfers the control circuit of selector TS from relay group to the B operators position at contact 343, and at contacts 345 opens the locking circuit of relay 305.

The calling toll line is now connected.

through both the A and B positions follows: The upper talking conductor 311 eX- tends by way of contacts 322, conductor 147,

contacts 127, 132, 134, and 137, conductor r un 148, contacts 325, conductor 353, wiper 413 of the finder switch F, contacts 427, conductor 248, contacts22'?, 232, 234, and 238, conductor 249, contacts 420, wiper 414, conductor 354,

and conductor 355 to toll selector TS. Lower talking' conductor 312 extends by way of contacts 323, conductor 146, contacts 128, 133, 135, and 139, conductor 149, contacts 320, conductor 349, wiper 409 of finder switch F, contacts 417, conductor 247, con-4 tacts 228, 233, 235, and 239, conductor 250,

contacts 416, wiper 408, conductor 348, and

conductor 358 to toll selector TS. A control circuitfor the toll selector is also coinpleted, this circuit extending from ground at the B position, contacts 222, resistance 208,

conductor 246, contacts 421, wiper` 410 of the finder switch F, conductor 350, contacts and 331, conductor 356, contacts 521,.and 536 f the wanted lineV The operation of relay 302'y in parallel through the winding of relay 502 to battery. Relay 502 is maintained 4in operated position over this circuit.

The operators telephone setsI at both inward and outward positions are bridgedn across the talking conductors ofthe line and m trunk as previously described for the inward operators set. The B operators set is identical with the previously described A opera- `torsset, and corresponding parts are similarly` designated in the drawings. The A opi5 erator may now pass the necessary information-to the B operator over the talking conductors in the above traced circuit. The toll line is temporarily disconnected by the 5 operation of the cut-oil key K6 at the in- 80 ward position which causes relay 103 to operate and open the talking conductors at contacts 132 and 133. After passing the information, the A operator will disconnect by restoring the key K of the toll line relay o group TR to normal, leaving the completion of the call to the B operator.

The B operator then actuates the dialling key K12 at the outward position, and the previously traced circuit of the iinpulsing relay of the toll selector is transferred from ground by way of contacts 222 to ground by way of contacts 223 and the impulsing conlVhen 3 5 tacts 230 of the calling device CD. the calling device is turned off-normal, the incoming branch of the trunk is disconnected in the same manner as previously described for the inward position. ln this case the relay 204 opens the talking conductors of the trunk at contacts 234 and 235. As the calling device returnsto normal, the circuit of relay 502 is interrupted at contacts 230 starting relay 404 of iindcr switch Fis?"-1 opened, and that relay restores and opens the circuit of relays 401 and 403 of the finder switch and relays: 302 and 306 of the relay group` TR. These relays all restore to normal. A circuit is closed from ground, ofi-'1120 normal contacts 415, contacts 430 through the winding of release magnet 407 to batteiy. The release magnet energizes and the Awipers of the i'inder switch are restored to normal position in the usual way, the release-3125 circuit being opened at the off-normal con- -tacts when the wipers reach 'the normal position. In the relay group TR, the Vrestorationk of relay 302 is without eiiect. Relay 306, however, on restoring switches the con-i130 trol circuitofrelay 502 of the toll-selcctor ffrom the.' lBv .position to thereinygroup by way of contacts 344 andr 328. -From this point, the supervisionand release or" vthe call is in the hands of A operator and is exactly the-.same asl that described in the previous connection.

` The circuits are also arranged tor toll rswitchingzservice, as previously stated, that is, they are. adapted to operate in a -tandem tollswitching centerfor connecting incom- -.ing and outgoing toll lines, such as thetoll lines TL andTL which are assumed. to eX- .tend to ditferent exchanges in the system.

The connecting of these two toll lines is carried out by either the A operator or the B` I operator at the toll switching center as vwill i :be described.

The toll-operator at` the distant exchange signals over the trunk comprising conductors 361` and 362 in the usual way, and the call lamp ofthe associated relay group TR lights to inform the A operator rof the call. .The

.Aoperator answers the call in the same manner as other incoming cal-ls and may elect to complete the call or pass it to the B operator Y. `for completion as in the previously described .connection. 'In either case, the operatorv lcompleting-the call will first dial thedigit assigned for toll switching service, where- Aon the toll selectorv TS will raise its wipers to the called level and select an idle trunk Hwhich-the toll connector trunks are accessible,

the shaftlsprings of the toll selector areoperated'and a circuit is closed for relayf507 at contacts 513. Relay 507 operates, disconnects the repeating coil R4 from the circuit and connects the talking conductors ofk A.the switch straight through to wipers -541 and 544. The shuntv around contacts 521 in the circuit of relay 502 is opened at contacts 536 so that the circuit will beV opened onl the operation of switching relay 501. Then an idle trunk is connected with, switching'relay 501 of the toll selector operates in .the usual way to connect the operating and talking conductors through to the -wipers of the switch. Assuming that the trunk selected in thiscase is the one comprising conductors -588 to 591, inclusive, terminating in toll connector TC, the control conductor overwhich Yrelay 502 was operated byway of contacts 521, isznow extended to the impulserelay 1 556 of the connector, by way of contacts 520,

wiper 543, andthe trunk conductor 590. Relay 556 of the toll connector operates; and

A completes the circuit of relay 555 whichalso -.-operates.

The latter relay prepares the-impulsing circuit at contacts `583, and .atncon- ,.tacts. 582-connects aholding ground. torelease trunk conductor 589 to hold the switching relay ofathe preceding toll selector operated. Returning now to the toll sector, relay 502 restoresv .following the opening of its circuit at contacts 521, and opens the circuit of relay 503. at -contacts 523. Relay 503 is slow to release and maintains its armatures actuated a short time after its circuit is opened, and maintains the circuit of relay 501 until the holding ground is returned over the release trunk connector. Relay 503 then restores, closes a point in the release circuit which, however, isv now opened at contacts 519 of the switching relay.

The operator now dials the i'irst digit of the number assigned to the wanted toll line,

and the circuit of relay 556 is interrupted by the operators callingdevice. As relay 556 falls back in response tov the' iirst impulse, a circuit is closed from ground, contacts 587, 533, and 560 through the winding of the slowrelease series relay 554 and the winding of verticalimagnet 557 to battery. The vertical magnet operates to raise the wipers one step.

" Relay 554 operates and completes an alternate impulsing circuit by way or' contacts 580 and oi-normalcontacts 561 which close on the vertical step of the wipers. The succeeding impulses are transmitted over the alternate circuit, the initial circuit being opened at contacts-560 when the oit-normal springs operate on the first vertical step. Shortly after the last impulse of the series, relay 554 restores, opensthe alternate impulsing circuit at contacts 580, and at contacts 581 prepares the circuit for the rotary magnet. The opertor new dials the iinal digit d responds dropping baci: to close a circuit from ground, contacts'587, 583, 561, 581, 57S and 570, through the winding of the rotary inagnet 558 to battery, and in parallel therewith Athrough the winding of slowacting relay 552 to battery. The rotary magnet operates to step the wipers around to the contacts of the wanted toll line. Slow relay 552 opcrates with the iirst impulse and remains operated throughout the series of impulses, closing an alternate point in the impulsing circuitv at contacts v57 5 to prevent interference by the busy relay as the wipers rotate over v busy contact.

Tf the'wanted toll line is busy in another connection, the test conductor of the line will Abe grounded either at theA associated relay group corresponding to the relay group TR, 1

or by a toll connector such as the connector T C. Immediately after the last impulse of the series and before slow-acting relay restores, a circuit is completed from the grounded test conductor, wiper 564, contacts 573 and 563, through the winding of busy relay 553 to battery. Relay operates, prepares a locking circuit for itself at contacts l 5( r opens. a point inthe impulsing circuit at contacts 578, andat contacts 579 connects the busy tone to the lower talking conductor of the trunk. This tone informs the operator that the wanted toll line is busy and the operator is expected to release the connection as will be described hereinafter. In case the wanted toll line is idle, the test conductor will be connected to battery at the associated relay group. Busy relay 553 of the connector will not operate at this time. When relay 552 restores shortly after the last impulse of the series, a circuit is closed from this battery on the test conductor, Wiper 564, contacts 572, upper winding ofv relay 551, contacts 576 and 582 to ground. Relay 551 actuates its light tensioned armature and completes a circuit for its lower winding at contacts 569. The lower winding of the relay energizes to fully actuate the armatures and the talking conductors of the switch are connected through to the wipers at contacts 566 and 571, a busying ground is connected to the test wiper at contacts 567, and the previously described impulsing circuit is disconnected from the rotary magnet at contacts 570 and connected to impulsing wiper 589 by way of contacts 588. If the selected toll line terminates in an automatic switch at the distant exchange, the completing operator may further set up a connection by dialling additional digits which are repeated by relay 556 of the connector over the impulsing circuit and wiper to the selected trunk. If the toll line termi nates in a manual position, the completing operator will apply ringing current to the line by actuating the ringing key of the position equipment (either key K2 of key K10) to signal the operator at the called exchange. After signalling the wanted exchange, the completing operator will disconnect her telephone set from the toll line by restoring the answering key (K or K18) and the holding circuit of relay 556 of the connector will be transferred to the relay group TR of the calling toll line by way of contacts 331, 344, and 328. Relay 304 of the relay group will remain locked up to ground at the release key K1. The two toll lines are thus connected together by way of the toll selector and toll connector with the alternating current responsive relay 301 of the relay group bridged across the conductors.

When the connection `is to be taken down o the A operator is to be recalled, either the calling or called operator will connect ringing current to the toll line to operate relay 301. Relay 301 on operating closes the circuit of lamp L through to the interrupter I and the lamp flashes to indicate this condition to the incoming operator. Before releasing the connection, the operator will actu'- ate the answering key K and challenge the line to determine whether the signal is a recall or a disconnect signal. Relay 302 will operate following the operation of the 7 answering key, and by means of the mechani thereby opening the circuit of relay 304 which i will restore and open the holding circuit of relay 556 at contacts 331. Relay 556 restores and opens the circuit of relay 555 which also restores. Relay 555 removes ground fromthe l release trunk conductor of the incoming trunk, and also opens the holding circuit of relay 551, which relay then restores. A circuit for the release magnet is closed at contacts 584 and the release magnet operates to l restore the switch wipers to normal, thecircuit being opened at off-normal contacts 562 which open when the wipers reach their normal or home position. In the toll selector, the removal of ground from the release trunk conductor permits the restoration of relay 501 which closes a point in the release circuit of the selector at contacts 519. Release magnet 510 then operates in the usual way to restore the switch wipers to their normal position at which time the release circuit `is opened at oit-normal contacts 512 and the circuit of relay 507 is opened at contacts 513.

riginating toll calls are handled by the B operator who functions as a recordingcompleting operator in this case.` By way of example, it will be assumed that the subscriber at substation A desires to call a subscriber at some distant point. When the call is initiated at substation A, lineswitch LS operates in the usual way to extend the calling line to an idle first selector such as the selector S. The calling subscriber then dials the toll operators code, for instance, the digit 0 and the wipers of selector S are raised to the tenth level. The wipers are then automatically rotated in the well known manner until an idle trunk, such as the trunk comprising conductors 484-486 extending to the toll recording circuit RC is encountered.

The calling line loop is extended via conducl tors 484 and 486 and the right-hand windings of repeating coil R6 to line relay 454. Relay 454 operates, closes a circuit for relay 455 at contacts 469 and at contacts 468 closes a circuit for lamp L5. Relay 455 operates, connects ground to release trunk conductor 485 at contacts 471 to hold up the switching relay of the selector S, and connnects ring-back tone to trunk conductor 486 at contacts 470. The ringback tone consists of intermittent impulses of ringing current supplied by the generator GEN through condenser C and is controlled'by the interrupter I2. The calling subscriber is advised by the tone that the call has been extended to the operator.

Lamp L5 lights over the previously traced circuit to inform the operator that a call is awaiting attention.

To answer the call, the operator actuates key K16 which bridges the telephone set T .across ithe'le'fthand windings of repeating ycoil R6 via conductors 252 and 253, cont-acts 232 and 233, contacts 227 and 228, conductors ,247 and 248, and contacts 474 and 477. A circuit is also closed from ground, lower YWinding of relay 451, contact-s 478, winding of relay 453, upper winding of relay 452 to battery. These relays energize in series. Relay 451 completes a locking circuit for its upper winding via. contacts 458 and contacts 472 of release key K17, prepares the operating circuit of toll selector TS at contacts 456.; prepares the supervisory circuit at contacts 457; and at contacts 459 closes a holding circuit for relay 455. Relay 452 completes 1a circuit for its lower winding in p rallel with relay 455 at contacts 462; opens the circuit of lamp L5 at contacts 460; and disconnects the ring-back tone from the calling line at contacts 461. Relay 453 opens the normal connection of talking conductors 481 and to the left-hand windings cf repeating coil -RGat contacts 463 and 466, these conductors now being extended via contacts 475 and 476 `of key K16, conductors 249 and 250, contacts 238 and 239 of key K10, contacts 234 and contacts 232 and 233, contacts 227 and 228 cf -key K11, conductors 247 and 248, and con- -tacts 474 and 477 to the windings of the repeating coil. Relay 453 also extends the control vconductor 482 to ground at position equipment P via contacts 456, 464,'and 473, conductor 246, resistance 208. and contacts 222.

The calling subscriber will then give the necessary information to the operator. Tf the call is one which the operator cannot readily complete, for example a call to a, distant city, the operator will record the necessary data and request the calling subscriber to lhang up and wait until called back. The data will be passed to an A operator by ticket :and this operator will set up a connection to .the distant toll office as soon as toll lines are available, as will be described in later Vparagraphs.

In the event that the call-is for a subscriber .in some nearby city, the operator may elect to complete the call while the subscriber waits on the line. After requesting the calling sub-A scriber to wait, the operator will actuate key 'K12 thereby extending control conductor 482 to ground via impulsing contacts 230 of calling 'device CD. The operator will then dial the code assigned to a. particular toll trunk, the impulses from the calling device over conductor 482 operating toll selector TS in the same manner as toll selector TS pre-- viously described. The selector TS will connect with an idle toll connector, for example, connector TC which will in turn connect :with the wanted toll line such as the line TL. The

opera-tor will then ring over the toll line by actuating key K10, or if the toll vline termiquired number to set up the connection at the distant exchange. In either case, when the subscriber at the distantl exchange is reached, the operator will restore key K16 and the calling and called subscribers will be connected in talking relation. Relay 451 will remain energized over its upper winding and will main` tain the holdingcircuits for relays 452 and 455. Relay 455 will maintain ground on the release trunk to hold up selector S and lineswitch LS. Relay 453 will restore, switch the control conductor from the operators set to ground at contacts 465, and will connect talking conductors 481 and 483 directly to the left-hand windings of repeating coil R6. Relay 454 Awill supply talking current to the calling subscriber and similar current will be supplied 'to the called subscriber from the distant exchange. There will be no battery connections to the toll line during the conversation.

No supervision is given the originating operator in case the called subscriber hangs Aup first. When the calling subscriber hangs up, relay 454 will restore and close a circuit from ground via interrupter I', contacts 457 and 467, lamp L5 to battery. Lamp L5 will flash to inform the operator that the calling subscriber has hung up. Before releasing the connection, the operator will actuate key K11 to connect ringing current to the toll line to give a disconnect signal to the operator at the distant exchange, or to release the switches in case the system is arranged for toll line dialling. The operator will then actuate key K17, opening the rcircuit of relay 451 which restores. Relay 451 in turn opens the circuit of relays 452 and 455l which also restore. Ground is disconnected from control conductor 482 by the opening of contacts 456 and toll selector TS and connector TC release as previoush7 described. Rel removes ground from release trunk conductor 485 which permits selector S and lineswitch LS to release.

The operator may listen in on connections ofthe above type by actuating the talking key of the associated trunk, such as the key K16 and the monitoring key K13 of the position apparatus. The actuation of this key closes the circuit of relay 202 which operates to prepare the monitoring circuit which corresponds in all respects to that described for the telephone set T.

The operator may also talk to either party alone in a connection by operating the key K16 and one or the other of cut-off keys K14 or K15. Key K14 closes a circuit for relay 204 which disconnects the called party. while key K15 closes a circuit for relay 203 which disconnects the calling party.

In the case of a. recorded toll call such as that previously referred to, the A operator on receiving the ticket containing the necessary data will select an idle toll line to the wanted oiiice, for example, the toll line TL and will actuate the answering key K of the associated relay group. Relays 802, 303, and 304 will operate as in the previously described connections. Busy lamp L1 will light and calling lamp L will remain dark. The operator will then actuate the dialling key K5 thereby completing a circuit from ground, impulse contacts 130, contacts 123, resistance 108, conductor 145, contacts 380 to the midpoint of the left-hand winding of repeating coil R and over the two conductors 361 and 362 of the toll line TL in parallel to a switch at the distant exchange. `The operation `ot the calling device will actuate the switches at the distant exchange in the usual manner.

In case the toll line TL extends to an operators position, instead of actuating key K5, the operator will actuate key K3 thereby projecting ringing current Vover the toll line. The operator at the distant exchange will then set up the required connection.

When the wanted subscriber has been connected up, or. prior to that time as is more desirable, a connection will be set up over the toll service trunks and switches to the subscriber who originated the call. This part of the connection may be set up by either the A operator or the B operator exactly as described previously for incoming toll calls.

The A operator will receive the usual answering and disconnect supervision. lVhen the calling subscriber hangs up, the A operator will again actuate key K3 to give disconnectvsupervision to the distant operator or to release the automa-tic switches in the distant exchange when such are used. The

Aconnection to the calling subscriber is then released as previously described by the actuation of release key K1. What is claimed is:

1. Ina telephone system, a toll line terminating ina manual switchboard, a local trunk terminating in an automatic switch, a link circuit at the switchboard individual 'to said line and said trunk for connecting the i link circuit at the switchboard individual to said line and said trunk for connecting the same, a branch of said trunk extending to a second manual switchboard, and means for directively operating said switch from said first switchboard over said trunk or from said second switchboard over said branch.

3. In a telephone system, a toll line terminating in a manual switchboard, a local trunk terminating in an automatic switch, a link circuit at the switchboard individual to said line and said trunk tor connecting the same, a branch of said trunk extending to a second manual switchboard, means for directively controlling said switch over said trunk from the first switch board, and means for estabiishing a talking connection between the switchboards via said branch and for rendering said switch directively controllable from the second switchboard over the branch.

l. In a telephonesystem, a toll line terminating in a manual switchboard, a local trunk terminating in an automatic switch, a link circuit at the switchboard individual to said line and said trunk for connecting the same, a branch of said trunk extending to a second manual switchboard, a control circuit tor said switch including a conductor of said trunk and a calling device at the first switchboard, and means for disabling said control circuit and for establishing an auxiliary control circuit for the switch including a conductor of said branch and a calling device at the second switchboard.

5. In a telephone system, a toll line terminating in an answering position, a local trunk terminating in an automatic switch, a link circuit at said position individual to the vline and the trunk for connecting. the same,

a completing position, and means effective when the line and the trunk are connected Jfor directively controlling said switch from either position to extend a connection.

6. In a telephone system, a toll line incoming to a toll switchboard, a local trunk terminating in aniautomtic switch, a link circuit at the switchboard individual to said line and said trunk for connecting the same, a branch of said trunk extending to a second switchboard, means at the second .switchboard for directively operating said switch over said branch to complete a talking connection from said line to a called subscribers line, said talking connection excluding the Vbranch of the trunk.

7. In a telephone system, a plurality of lines incoming to a toll switchboard, an answering key for each line, a transfer key common to said lines, a second switchboard, operators telephone sets at each switchboard, a signal at the second switchboard, means responsive to the actuation of one of said answering keys for connecting the associated linge to the operators set at the first switch board, means responsive to the actuation of the transfer key for marking the connected line and for operating said signal, and a key at the second switchboard for disabling said signal and for connecting'the marked line with the operators set at the second switchboard.

8.VV In a telephone system, a toll line incoming to an operators position, a key for said line, a second key at said position, a second operatorfs position, a signal and a key at said second position, means responsive to the operation of both of said keys at the first position for marking said line and for operating .said signal, and means responsive to the operation of the key at the second position for disabling said signal and for connecting said line to the second position.

9. Ina telephone system, a tollline, an answering key for said line, two operators telephone sets, a transfer key associated with each set, a finder .switch associated with the second set, means responsive to the actuation of said answering key for connecting said line to the first set, and means responsive to the operation of said transfer keys for operating said finder switch to connect said line with the second set.

10. In a telephone system, a toll line, an answering key for said line, two operators telephone sets, a transfer key associated with each set, meansjresponsive to the actuation of said answering key for connecting saidv line to the first set, and means responsive to the actuation of both transfer keys for connecting said line with said second set.

k11. In a telephone system, a toll line, an answering key for said line, two operators telephone sets, a transfer key associated with each set, a signal for the second set, means responsive to the operation of said answer- Yin g key for connecting said line with the rst r-having a branch extending to a completing position, a vlink circuit at the answering position individual to the line and the trunk for connecting the same, a finder switch at said second position, and means controlled jointly from said two positions for operating said iinder switch to complete a talking connection between the positions via said branch and said link circuit.

13. In a telephone system, a toll line incoming to an answering position, a trunk having a branch extending to a completing position, a link circuit at the answering position individual to the line and the trunk for connecting' them together, a train of automatic switches, means at the completing position for directively operating said switches over said branch to extend a connection from said toll line to a subscribersline, and means in said link circuit for controlling the release of said connection.

14. In a telephone system, a toll line, ktwo operators oositions tele )hone sets at each position, an automatic switch, means including a link circuit for connecting the toll line with said switch and with the telephone set at the iirst position, means at the'tirst'position for signalling the operator at the second position, a key at the second position for answering the signal, and means responsive to the operation of said key for connecting said two telephone sets in talking relationship and for placing said switch under control of the operator at the second position.

15. In a telephone system, a toll recording trunk incoming to a manual switchboard, means for extending a call to the switchboard via said trunk, means at the switchboard for answering the call, .means responsive to the answering of the call for extending a connection from the trunk to an automatic switch, and means at the switchboard for directively operating said switch to extend a connection to an outgoing toll line.

16. In a toll switching system, answering and completing positions, a toll line incoming to the answering position, a toll switch train directively controlled from either position for extending a connection to a subscribers line, and a link circuit at the answering position individual to the toll line for connecting the same with said switch train.

17. In a telephone system, a toll line terminating in an answering position, a local trunk termin ating at said position, a branch of said trunk extending to a completing position, a link circuit at the irst position, means including the link circuit for answering calls extended over said line and for connecting said line and said trunk, and means including a switch controlled jointly from said two positions for completing a talking connection between the positions over said branch.

18. In a telephone system, a cordless toll switchboard comprising two positions, toll lines, means at the first position for answering calls extended over said toll lines, means for transferring the calls to the second positon for further extension to another toll line or to a subscribers line, means for disconnecting the second position when the extension is completed, and means at the first position for supervising the calls so extended.

19. In a telephone system, a cordless toll switchboard comprising two positions, toll lines, means at tlie first position for answering calls extended over said toll lines, means for transferring the calls to the second position for completion of the connections via automatic switches, and means at the first position for supervising the connections completed from the second position and for releasing the switches engaged in such calls.

20. In a telephone system, a cordless toll switchboard comprising two positions, toll lines, means at the iirst position for answering calls extended over said toll lines, automatic switches for extending connections from calling toll lines to called toll lines or subscribers lines, and means at each position for directively operating said switches.

21. In a telephone system, acordless toll switchboard comprising two positions, toll lines, means at the first position for answering calls extended over said toll lines, automatic switches for extending connections from calling toll lines to called toll lines or subscribers lines, means for directively controlling said switches from the first position, and means for transferring the directive con-- trol of said switches from the rst position to the second position.

22. In a telephone system, a toll switchboard comprising two positions, toll lines incoming to the first position, toll selectors, service trunks extending from the irst position to said toll selectors, link circuits indi- Vidual to said service trunks for connecting the same with said toll lines, recording trunks incoming to the second position, other toll selectors, service trunks extending from the second position to said other toll selectors, link circuits individual to the second said service trunks for connecting the same with said recording trunks, toll line connectors accessible to all of said toll selectors, and means at each position for operating the associated toll selectors and any of said toll line connectors to extend connect-ions to said toll lines.

23. In a telephone system, a line, a trunk, a link circuit connecting the line and the trunk, an operators position circuit, means for splitting the link into two sections and for bridging the gap between the sections by said position circuit, a second operators position circuit, means for splitting one section of the link circuit into two sub-sections, and means for bridging the-second gap by said second position circuit.

24. In a telephone system, a line, a trunk, a link circuit connecting the line Vand the trunk, an operators circuit, means in the link for interposing the operators circuit in the connection between the line and the trunk, a second operators circuit, and means for interposing the second operators circuit in the connection between the iirst operators circuit and the trunk.

25. In a telephone system, a plurality of lines, a like plurality of trunks, line circuits connecting the lines and trunks, an operators circuit common to said links, means for splitting any link into two sections and for closing the gap between sections through said common circuit, a second operators circuit, and means for splitting one section of the split link into two sub-sections and for closing the gap between sub-sections through said second operators circuit.

In witness whereof I hereunto subscribe my name this 14th day of January, A. D. 1930.

THOMAS F. CROCKER. 

